Background:. Metastatic invasion of axillary nodes is an important prognostic factor in breast cancer. Formal axillary 
dissection is an integral part of the surgical treatment, however, in many patients proved to have been unnecessary after 
histological node examination. Various imaging techniques failed to help. On the assumption that B-mode ultrasonography of the axilla using updated electronics and sensitive transducer and applying the criterion of combination of different sonographic features, this prospective study was done to evaluate the role of axillary ultrasonography in diagnosing axillary lymph node metastasis of breast cancer. 
Methods: Forty consecutive patients with breast cancer who were treated within four weeks from the ultrasound 
examination of their ipsilateral axillae by formal axillary dissection with lumpectomy or mastectomy. The 
histopathological results were related to the ultrasonographic findings. Sensitivity and specificity of the examination were calculated. 
Results: Abnormal lymph nodes were demonstrated in 19 axillae, only 10 of which were clinically detected. The sensitivity of sonogrpahy in detecting malignant nodes was 76% , the specificity 82.5% and the positive and negative predictive value 94.7% and 71.4% respectively. 
Conclusion:. The present results demonstrated that, though axillary sonography allows the detection of abnormal lymph 
nodes which are clinically undetected, yet, with sensitivity and specificity less than 90%, Therefore ultrasongraphy may not be a sufficiently effective noninvasive method for diagnosing axillary lymph node metastasis in patients with breast 
carcinoma.